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<A NAME="MPI_Dist_graph_create_adjacent"><H1>MPI_Dist_graph_create_adjacent</H1></A>
returns a handle to a new communicator to which the distributed graph topology information is attached. 
<H2>Synopsis</H2>
<PRE>
int MPI_Dist_graph_create_adjacent(MPI_Comm comm_old,
                                   int indegree, int sources[], int sourceweights[],
                                   int outdegree, int destinations[], int destweights[],
                                   MPI_Info info, int reorder, MPI_Comm *comm_dist_graph)
</PRE>
<H2>Input Parameters</H2>
<DL>
<DT><B>comm_old </B><DD>input communicator (handle)

<DT><B>indegree </B><DD>size of sources and sourceweights arrays (non-negative integer)

<DT><B>sources </B><DD>ranks of processes for which the calling process is a
destination (array of non-negative integers)

<DT><B>sourceweights </B><DD>weights of the edges into the calling
process (array of non-negative integers or MPI_UNWEIGHTED)

<DT><B>outdegree </B><DD>size of destinations and destweights arrays (non-negative integer)

<DT><B>destinations </B><DD>ranks of processes for which the calling process is a
source (array of non-negative integers)

<DT><B>destweights </B><DD>weights of the edges out of the calling process 
(array of non-negative integers or MPI_UNWEIGHTED)

<DT><B>info </B><DD>hints on optimization and interpretation of weights (handle)

<DT><B>reorder </B><DD>the ranks may be reordered (true) or not (false) (logical)
</DL>
<P>
<H2>Output Parameter</H2>
<DL><DT><B>comm_dist_graph </B> <DD> communicator with distributed graph topology (handle)
</DL>
<P>
<H2>Thread and Interrupt Safety</H2>
<P>
This routine is thread-safe.  This means that this routine may be
safely used by multiple threads without the need for any user-provided
thread locks.  However, the routine is not interrupt safe.  Typically,
this is due to the use of memory allocation routines such as <TT>malloc
</TT>or other non-MPICH runtime routines that are themselves not interrupt-safe.
<P>
<H2>Notes for Fortran</H2>
All MPI routines in Fortran (except for <TT>MPI_WTIME</TT> and <TT>MPI_WTICK</TT>) have
an additional argument <TT>ierr</TT> at the end of the argument list.  <TT>ierr
</TT>is an integer and has the same meaning as the return value of the routine
in C.  In Fortran, MPI routines are subroutines, and are invoked with the
<TT>call</TT> statement.
<P>
All MPI objects (e.g., <TT>MPI_Datatype</TT>, <TT>MPI_Comm</TT>) are of type <TT>INTEGER
</TT>in Fortran.
<P>
<H2>Errors</H2>
<P>
All MPI routines (except <TT>MPI_Wtime</TT> and <TT>MPI_Wtick</TT>) return an error value;
C routines as the value of the function and Fortran routines in the last
argument.  Before the value is returned, the current MPI error handler is
called.  By default, this error handler aborts the MPI job.  The error handler
may be changed with <TT>MPI_Comm_set_errhandler</TT> (for communicators),
<TT>MPI_File_set_errhandler</TT> (for files), and <TT>MPI_Win_set_errhandler</TT> (for
RMA windows).  The MPI-1 routine <TT>MPI_Errhandler_set</TT> may be used but
its use is deprecated.  The predefined error handler
<TT>MPI_ERRORS_RETURN</TT> may be used to cause error values to be returned.
Note that MPI does <EM>not</EM> guarentee that an MPI program can continue past
an error; however, MPI implementations will attempt to continue whenever
possible.
<P>
<DL><DT><B>MPI_SUCCESS </B> <DD> No error; MPI routine completed successfully.
</DL>
<DL><DT><B>MPI_ERR_ARG </B> <DD> Invalid argument.  Some argument is invalid and is not
identified by a specific error class (e.g., <TT>MPI_ERR_RANK</TT>).
</DL>
<DL><DT><B>MPI_ERR_OTHER </B> <DD> Other error; use <TT>MPI_Error_string</TT> to get more information
about this error code. 
</DL>
<P><B>Location:</B>dist_gr_create_adj.c<P>
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